A Comment on the Yayoi Period Dating Controversy

SHŌDA Shinya 庄田慎矢

Korean Institute for Archaeology and Environment

publ.: March 2007

Introduction

In May 2003, the National Museum of Japanese History (NMJH) announced, that the beginning of Yayoi
period dates back to 500 years earlier than it had previously been thought; charred remains stuck to
pottery samples had been analysed by AMS 14C dating (HARUNARI et al. 2003). A few archaeologists
accepted the new dating right away, while many scholars expressed critical opinions.

Especially the archaeologists in the Kyūshū region, who had been playing a leading role in the
dating of Yayoi period, strongly rejected it. The reason for this may be found in the great
confidence archaeologists use to have in the dating of the Yayoi period, which after all had kept
unchanged for nearly 50 years. And moreover, the NMJH announcement lacked evidences in several
points; subsequently it was not possible to persuade the audience to fully agree to the new dating.
After more than three years, there are still various contrary opinions, not only addressing the
chasm between the methods of natural science (14C dating) and 'purely' archaeological approaches
(typological cross-dating). Even among merely archaeological perspectives different beliefs add to
the controversy.

Why is this controversy going on? And why is it important? Isn't it just a recurrence of the '14C
revolution' in the Japanese Archipelago?

In this paper I attempt to explain what kind of discussion is currently going on relating to this
subject, and evaluate its meaning. Actually, a lot of articles have already been published, but
almost all of them in Japanese; very few appeared in English.[fn. 1] For an interested international
audience it is in consequence difficult to follow this highly intriguing discussion.

Three years ago, I already made a brief presentation on this matter in English at the 3rd World Wide
SEAA Congress in Daejeon, South Korea (SHŌDA 2004a).[fn. 2] I have also written some essays on this subject
in Japanese (2004b; 2006), and Korean (2005). The following essay, however, aims at introducing the
many discussions that are going on, rather than stressing the author's opinion. It has to be
emphasized, that there is no factual consensus yet, and the conclusions I draw are open to
modification. I will start this essay with looking back on the history of 14C dating in Japan and on
the traditional dating of the Yayoi period. I will then focus on various new opinions connected to
the subject, and in conclusion discuss the problems and meaning of the Yayoi dating controversy.

14C Dating in Japanese Archaeology

In Japan, 14C-dating was applied in 1951 for the first time (LIBBY 1951:295). A charcoal remain was
examined, excavated from a dwelling pit in the vicinity of the shell mound of Ubayama (Ubayama
kaizuka 姥山貝塚) in Chiba Prefecture, which belongs to the Middle Jōmon period. As ISHIKAWA (2006:60)
mentioned in his paper, it was no later than at the end of the 1950s that Japanese archaeologists
started to recognize the importance of 14C-dating. In studies focusing specifically on the dating of
the Yayoi period, references to 14C dating as well began to appear (MORI 1968). However, many
Japanese archaeologists seemed to regard 14C dating less effective than the chronological sequences
they had achieved by typological method over a long period of time. In typological studies of Yayoi
pottery (Yayoi doki 弥生土器) or Sueki 須恵器 pottery from the Kofun period the time
span of each chronological phase represented less than 30 years, thus apparently being much more
precise than 14C dating.

Bronze mirrors from Han 漢 dynasty China are a common find in latter Yayoi period elite burials, and
the production time of many of them is known in absolute dates. The approximate calendar year of a
Yayoi find therefore - at least from the 1st century B.C. onward - was already known, while 14C
dating obviously offered a much wider range of chronological results. 14C dating thus appeared
useless within a Yayoi framework, contrary to the situation of the previous cultural phases in
Japan. SAHARA (1981:12) accordingly wrote, "The archaeologist who use 14C dating in Yayoi period,
just select the dates which are fit to their opinion from various data." And not only with regard to
relative chronology, but also about absolute dating, there was a serious controversy between 14C
dating and typological cross-dating in the 1960s. [fn. 3] YAMANOUCHI and SATO (1962) strongly denied the 14C
dating of Natsushima shell-mound (Natsushima kaizuka 夏島貝塚, CRANE et al. 1960), which postulated
Jōmon pottery is the oldest in the world, by comparing the artefacts of the continent and the
Japanese Archipelago.
Even now, many Japanese archaeologists think highly of their achievements of those days. Dates were
determined by 'archaeological' methods without relying on 14C. Unfortunately, the material at that
time was too limited to reveal that 'long chronology' (chōki hennen 長期編年) is possible purely by
cross-dating. As IMAMURA (2005:183) mentions, in consequence of YAMANOUCHI's opinion many Japanese
archaeologists are reluctant to follow 14C dating even now, and feel shame to rely on it.
It is too easy to just 'believe' the dates offered from a laboratory; dating and chronology was (and
is) one of the most fundamental and important subjects in Japanese archaeology. If small pieces of
charcoal tell everything, many efforts spent on typological study become meaningless, if I may carry
this line of reasoning further.

So for a long time, typology and 14C-dating were in a delicate relation (YOSHIDA 2005:37). However,
like TSUJI (1999) recently has shown by means of the dating of Sannai-Maruyama 三内丸山 site, AMS 14C
dating and typological chronology actually can coincide in their results. Few scholars regard 14C
dating as absolutely nonsense, but many archaeologists think that it is necessary to have 14C
results checked by typological method.

Yayoi period dating as it used to be

As mentioned above, 14C dating was initially applied to determine the beginning of the Yayoi period
in the late 1960s (MORI 1968). However, some scholars offered similar dates for the Yayoi period
even before that. For instance, KOBAYASHI (1951) and SUGIHARA (1961) presented the dating of Yayoi
period using mirrors and coins from China, without 14C data. Both studies described the date of the
beginning of Early Yayoi as 3rd or 2nd century BCE. In the 1970s OKAZAKI (1971) and HASHIGUCHI
(1979) also assumed the beginning of Early Yayoi at about 300 BCE.

Around this time the definition of 'Yayoi period' began to change. Paddy fields, a characteristic
feature of the Yayoi culture, were excavated in Itazuke 板付 (1977-78) and Nabatake 菜畑 (1980-81)
sites, but they belonged to the stage of Yu'usu-type pottery (Yu'usu-shiki doki 夜臼式土器), which had
been considered as Final Jōmon. SAHARA (1983:5) suggested that this stage should be incorporated
into the Yayoi Period and called it 'Initial Yayoi' (Yayoi sōki 弥生早期). The dating of Yu'usu-type
pottery was considered to be 5th to 4th century BCE, as this stage was thought to precede Early
Yayoi only slightly (e.g. OKAZAKI 1971). From that time on the beginning of the Yayoi period has
been regarded as dating from the 5th century BCE.

According to the increase of excavated material from the Korean Peninsula, some scholars on the
other hand investigated the dating by using material other than Han dynasty mirrors or coins
unearthed in Japan. They focused on lute-shaped (or Liaoning type) bronze daggers
[fn. 4], a find
distributed in China, Korea, and Japan. This type of bronze dagger dates back to the end of the 9th
century BCE, so it is very useful for estimating the beginning of the Yayoi period. In Japan,
however, only one example is extant coming from Imagawa 今川 site in Fukuoka Prefecture, which
belongs to Early Yayoi. Thus the Korean materials (over 60 pieces) were used alternatively to
determine the date. Some of the daggers have been excavated together with pottery or stone tools
that have a firm position in relative chronology. Moreover, cross-dating of pottery or stone tool
between the southern part of the Korean Peninsula and northern Kyūshū has been done in detail. It is
therefore possible to date the Yayoi period by using these materials. TAKESUE (2002:3), for example,
determined the beginning date of Yayoi period at the 6th or 5th century BCE, according to the above
mentioned method and to tree-ring dating.
As early as in 1996 it was, moreover, announced that the Middle Yayoi in the Kinki 近畿 area should be
re-dated a hundred years back. In Ikegami-Sone 池上曽根 site the wooden pillar of a building, belonging
to the later part of Middle Yayoi, had been dated 52 BCE by dendrochronology. That was about a hundred
years earlier than the date commonly accepted (MITSUTANI 2000:47). The influence of this re-dating,
however, was limited to the Kinki area. Kyūshū or other areas were not involved, although on the
other hand the new dating somehow solved the gap that existed until that time between Kyūshū and
Kinki chronologies. As mentioned above, TAKESUE postulated the earliest date for the beginning of
Yayoi, by making use of new material, before the NMJH announcement. The NMJH, however, presented
their conviction of an even much earlier date only one year later.

Old opinions vs. new opinions

The National Museum of Japanese History claimed the new dating of the Yayoi period in May 2003.
Initially the discussion seemed to become a mere conflict between 'believers' and 'sceptics'. Three
months later, a meeting took place in Tōkyō [fn. 5]with the aim of rethinking the archaeological evidence
of the traditional dating, i.e. the short chronology (tanki hennen 短期編年). Some of the scholars there
admitted that the evidences which had determined the dating of the Yayoi period was not accurate,
even if there were still many archaeologists who insisted on the short chronology and its 'evidences' like TAKAKURA (2003) and HASHIGUCHI (2003). These scholars strongly rejected the NMJH's
opinion by presenting some evidence which supported the old, short chronology.

Many of the evidences in favour of a short chronology, however, have problems within their
archaeological context. For example, the ironware from dwelling pit no. 16 in Magarita 曲り田 site is
one of the most important evidences produced in this discussion. The dwelling belongs to Initial
Yayoi, so it shows that ironware already appeared during this stage. In the Korean Peninsula
ironware is thought to have been introduced by the state of Yan 燕 in the Chinese zhanguo 戰國 era, 5th
– 3rd century BCE (e.g. SHIOMI 1982:225). Thus the date of Initial Yayoi cannot be earlier than
that. However, the Magarita dwelling pit is overlapped by some other archaeological features and
'the ironware' is just a fragment which is no larger than about 3 cm, reported as "excavated near
the floor".

There is additional 'evidence' from China playing an important role in the dating: bronze dagger and
zhanguo era's (Chin.) mingdao 明刀 coin finds from Loushang 楼上 tumuli site in Liaoning 辽宁 province.
AKIYAMA (1969:25) dated the newer type of lute-shaped daggers as lasting until the 3rd century BCE
according to this 'combination'. Although LIN (1980:150) pointed out that these materials have not
beyond doubt been unearthed together, the majority followed the dates by AKIYAMA. Actually,
according to the site report these finds were not excavated by archaeologists, but donated by a
junior high school student who happened to live in the vicinity of the site. GOTŌ (2005:36) also
pointed out this problem, and claimed a necessity for a re-examination of the material to support
the dating.

ŌNUKI Shizuo is among those who have long been arguing in favour of the long chronology, even though
his full paper on this subject was published no earlier than 2005 (ŌNUKI 2005). He pointed out that
in North Korea, there was a shift from short chronology to long chronology in accordance with new
materials unearthed in China, such as Nanshangen 南山根 excavated in the 1960s (ŌNUKI 2003:40). We also
know of Zhou 周 dynasty wares with calendar year inscriptions from the 1st millennium BCE.
Archaeologists are thus able to date the materials of this age, such as the above mentioned
lute-shaped bronze dagger, without carbon dating. A problem concerns the so-called 'inclined
chronology' (keisha hennen 傾斜編年), which is based on the perception of a long time lag between the
same type of find depending on its location in the centre or in the periphery of a culture. Ōnuki
criticized, that in previous studies the dates of the finds from the periphery were considered much
too young owing to the adoption of the inclined chronology (ibid.:42).

Unfortunately, historical events were also used to support this inclined chronology. The bronze
dagger with narrow blade (sehyeong donggeom 細形銅劍) is the type of dagger following the lute-shaped
one in the Korean Peninsula. The distribution of this dagger is limited to south of Cheongcheon 淸川
River, while the distribution of mingdao coins is limited to north of it. YUN (1972:124-127) linked
these distributions to events in historical records such as the Shiji Xiongnu Liezhuan 史記匈奴列傳 and
the Weilue 魏略. The historical records tell about the invasion of the Liaodong area by a Yan general
named Qinkai 秦开. Qinkai served king Zhao 昭王, who was on the throne during the years 311 to 279 BCE.
YUN assumed that the lute-shaped daggers continued to exist until this time, and were then replaced
by the narrow dagger, thus mirroring the major political changes in Liaodong. YUN considered the end
of the lute-shaped dagger at the end of the 4th century to the beginning of the 3rd century BCE.
This, however, is not logically acceptable because there is no evidence that narrow-bladed bronze
daggers appeared at the same time as mingdao coins. Although it seems an absolutely groundless
argument, it made many archaeologists believe in the short chronology. YUN's argument was based on a
dating that many archaeologists assumed to be correct at that time. On the other hand, YUN's linking
of find distributions with historical events somehow ended up with the conviction of archaeologists
that the dating is built on firm grounds of historical events. It was very hard to get out of this
circular reasoning once it had started.

In South Korea the lute-shaped dagger has been dated as early as the 8th century BCE in the 1990s,
in accordance with the bronzes from north-eastern China (YI 1992:131). This 'long chronology' was,
however, only addressing the appearance of the lute-shaped dagger; the dating of the subsequent
narrow-bladed dagger was not influenced. Thus the period of lute-shaped daggers was enlarged by
almost 500 years in the Korean Peninsula. This dating was widely accepted in Korea. However,
Japanese scholars did not follow this dating. While the long chronology was accepted in the 1990s in
Korean archaeology, in Japan archaeologists continued to favour the short chronology (SHŌDA
2006:144). As a result, a gap of about 300 years arose regarding the early 1st millennium BCE
between Korean and Japanese perceptions, although for the later phase common viewpoints and dating
existed.

After the announcement by NMJH, two Japanese leading scholars on bronze wares in north-eastern Asia
nevertheless changed their standpoint from short chronology to long chronology (see MIYAMOTO 2004;
OKAUCHI 2004). MIYAMOTO (2004) regards the beginning of Yayoi as no earlier than 9th century BCE;
TAKESUE (2004) and myself (SHŌDA 2005) as no earlier than 8th century BCE according to
cross-chronology, independent from AMS data. Both opinions postulate younger dates than those
presented by NMJH. They consider the 10th century BCE date of NMJH as too early when checked by
typological cross-dating.

Discussion

The majority of the archaeologists is aware of the need to change the viewpoint for North East
Asia's 1st millennium BCE, especially in the Korean Peninsula and Japanese Archipelago. Still
various contradictory opinions exist. It is not the simple question whether to believe in AMS or
not. As ŌNUKI (2005:106) stresses, the most important point in this discussion is that 14C dating
made many archaeologists aware of the necessity to reassess the typological studies they made.
Still, many problems are left on all sides, either concerning AMS dating or typological cross-dating
using inscribed wares from China.

For instance, ISHIKAWA (2006) criticizes not AMS dating itself, but the way NMJH interprets the
data. IWANAGA (2005), on the other hand, pointed out the difficulties and logical problems in
cross-dating. For the material that has been the focus of the AMS dating itself, YOSHIDA (2005:54)
warned that "the problem is, that we don't know what the charred material actually was." NMJH
announced that the Initial Yayoi dates back to the 10th century BCE, but there are only three
samples for the earlier part of Initial Yayoi (FUJIO et al. 2005:82). Moreover, the samples
presented contain a sherd, which is the mere bottom part of a pottery, and we cannot identify to
which type it belongs. NMJH thus determined the date of the beginning of the Yayoi period mainly on
the basis of AMS dates from the later part of Final Jōmon and the later part of Initial Yayoi, and
they still have not fulfilled the duty to explain. The evidence NJMH presented is not enough to make
many scholars understand and agree.

Cross-dating from Chinese central plain also faces problems due to the shortage of materials. Only
five examples of lute-shaped bronze daggers have been unearthed in China in assemblages of bronze
wares which can be absolutely dated. The pottery chronology for this area, moreover, is not distinct
enough to discuss the dating in detail. Many scholars wrote papers on lute-shaped bronze daggers in
China, North and South Korea, and Japan, but they had not compared and referred to each other
sufficiently (SHŌDA 2006:134). Research on this subject should be practiced from a broader point of
view.

As I pointed out at the beginning, conclusions are still open to modification. It is important to
compare the results of these two absolutely independent methods and to investigate the difference
and its reason. There is no need to look for common ground right now. The announcement in 2003
influenced Japanese archaeology dramatically, but unlike the 'second radiocarbon revolution' in
Europe (RENFREW 1973:94), the framework did not 'collapse'. This change of dating will never
transform the megalithic structures or metallurgy of Japan into the earliest in East Asia.

It is possible in north-eastern Asia to salvage large parts of the traditional structures,
especially with regard to their relative position in each area. But the circumstances change when it
comes to crossing 'the fault zone' in the Korean Peninsula. Inclined chronology 'solved' the
time-lag by enlarging the time span of Korean Early and Middle Bronze Age – which means the age of
the lute-shaped bronze dagger – and by connecting the old dates of the inscribed wares with the
younger dates, which are believed to be Yayoi period.

In consequence, the cross dating of China-Korea or Korea-Japan needs to be corrected. It includes
reassessing the diffusion of bronze and iron from China eastwards. In South Korea, abundant
archaeological data have been unearthed recently through numerous rescue excavations. They will help
both typological study and 14C dating.

Conclusion

The dating controversy cannot be schematised as that archaeological typology suffered defeat to
carbon dating. In Japan also, the relationship between the two methods is getting more cooperative
than in the past. Again, it is important to verify each other by comparing the results of different
methods based on different principles and to discuss the differences and the reasons for that. Now
archaeologists have to reconstruct the history of the 1st millennium BCE not only in Japan, but also
for the whole of North East Asia. Inclined chronology was denied and we have to reassess the
relationship between centre and periphery, not only from a passive perspective but more
simultaneously and interactive.

This essay mainly dealt with the beginning date of Yayoi period, but there are more complicated
problems when it comes to determine Early and Middle Yayoi periods. I will refer to it at the next
opportunity.

Acknowledgement

I would like to thank Barbara SEYOCK, Michael MOOS and LEE Heejin, for helping me to write this
article. GOTŌ Tadashi, ŌNUKI Shizuo, and KUNIKITA Dai, moreover gave me many helpful advices on this
subject. I am, of course, alone responsible for the content.

Footnotes

1) As far as I know,
KEALLY ’s critic (KEALLY 2004) was the only one, but
unfortunately his article’s quotations are mainly from newspapers, not academic papers. It should be
noted that what newspapers wrote is NOT what most of archaeologists thought and discussed. In Korea,
an article introducing this controversy appeared in Journal of the Korean Archaeological Society,
the leading journal in Korean archaeology (CHOI 2006). It shows that there is a lot of interest in
this topic.

2)Fumiko IKAWA-SMITH, moreover, organized and chaired a session on the
'Problems presented by the AMS Radiocarbon Dates for the Yayoi Period in Japan' at the same
conference, thus initiating a first international platform for discussing the topic (IKAWA-SMITH
2004). Unfortunately, the papers have not been published since. The session comprised presentations
of Fumiko IKAWA-SMITH, FUJIO Shin'ichirō and SAKAMOTO Minoru (National Museum of Japanese History),
TAKAKURA Hiroaki (Seinan Gakuin University) and MIZOGUCHI Kōji (Kyūshū University), and discussants
were Sarah M. NELSON (University of Denver) and Gina L. BARNES (University of Durham) [see program
and abstracts in SEAA-web >> Archive >> SEAA Conferences
>> Daejon 2004 Session 4-B (editor's note)].

IKAWA-SMITH 2004, Yayoi in the East Asian interaction sphere: Problems presented by the AMS
radiocarbon dates for the Yayoi period in Japan (abstract), In: SEAA, Korea 2004, Third
International Congress of the Society for East Asian Archaeology (Program). Daejeon: Chungnam
National University, p. 83.